Repro Flashcards
four phases to the canine ovarian cycle or estrous cycle
protestrus, estrus, diestrus, and anestrus
proestrus period
– traditionally associated with the start of vaginal bleeding and is under the influence of the hormone estrogen
– pulses of follicle‐stimulating hormone (FSH) and luteinizing hormone (LH) that result in the increase of both hormones
– Vaginal cytology at this time usually shows red blood cells, varying degrees of neutrophils, frequent bacteria, and initially parabasal and intermediate epithelial cell
estrus period
– characterized by being “in heat
– Serum estrogen concentrations peak just before the onset of estrus and then begin to fall, reflecting the final maturation process of ovarian follicles several days before ovulation
– cats are induced ovulators, meaning that this species does not reach ovulation until mating occurs
diestrus period
– time following mating and is associated with corpus luteum activity and potential pregnancy
– Progesterone concentrations rise as estrogen concentrations decrease
anestrus period
– phase of the female reproductive cycle in which the uterus involutes
– Anetrus begins with whelping and ends with proestrus
Gestation Length
– Dogs: can range from 55 to 72 days
– Cats: 62 to 67 days
Pyometra
– bacterial infection in the uterus associated directly with the estrous cycle
– generally develops within three months after estrus
– During proestrus and estrus, the cervix is open, allowing for normal vaginal flora and possibly perineal or fecal bacteria to ascend into the uterus
– Following the estrus phase, the cervix closes, essentially locking in bacteria and allowing proliferation if the uterus is unable to overcome the bacteria using its own defenses
– release of progesterone from the ovaries leads to decreased uterine contractions and increased glandular secretions, and promotes development of the mucous lining of the uterus.
– development of cystic endometrial hyperplasia occurs
Escherichia coli is the most common organism
What does “open vs closed” pyo referring to?
– Pyometra is classified as either open or closed as indicated by the cervix
Metritis
– referred to as endometritis, is an infection of the uterus that, unlike pyometra, occurs postpartum when progesterone levels are low
– Clinical signs are similar to pyometra
– prediposing factors include: dystocia, retained fetus, contamination during medical intervention for dystocia, and septic mastitis.
Difference between treating Metritis and Pyometra
– difference in treating metritis versus pyometra is that metritis often responds well to medical therapy due to the decrease in progesterone production
Mastitis
– occurs in lactating females, is simply defined as inflammation of the mammary gland.
– inflammation can be septic or non‐septic
Non‐septic mastitis is called
– galactostasis, or impaction of milk
– often arises when the young are not nursing from all mammary glands
– Gentle manipulation and encouraging the young to nurse from different glands can help relieve the impaction
Causes of dystocia
- primary uterine inertia (i.e. the uterus fails to contract with sufficient force due to inherited breed‐related causes),
- secondary uterine inertia (i.e. the uterus fails to contact with sufficient force due to exhaustion, electrolyte disturbance, hypoglycemia, dehydration, etc.)
- dam conformation, pelvic narrowing secondary to pelvic trauma or neoplasia, uterine torsion, or uterine prolapse
normal parturition period
Divided into 3 labor stages
Stage one labor
– changes that often go unnoticed by the client
– uterus begins to contract, the cervix dilates, and body temperature begins to fall to 36.1–37.2 °C (97–99 °F)
– decline in body temperature coincides with the decline in progesterone. Stage 1 labor usually lasts 6–12 hours, but may last up to 24 hours
Stage two labor
– what most people consider true labor
– Strong contractions begin and a clear vaginal discharge will be noticed prior to the delivery of each neonate.
– expulsion of the newborn occurs within several hours of the initiation of stage 2.
– Stage 2 can last 12–24 hours in dogs and up to 36 hours in cats, with up to an hour between the birth of each puppy or kitten.
Stage three labor
– involves the passing of the placenta.
– often happens along with stage 2, as placenta will be passed after each fetus.
– If multiple fetuses are passed within a short amount of time, the placentas will follow together.
Uterine inertia
occurs when the uterus is unable to push the fetus into the birth canal due to poor myometrial contractions.
– can be primary, including genetic, mechanical, hormonal, or physical components
–
Primary uterine inertia
is suspected when stage 2 labor never appears to begin
Secondary uterine inertia
more common and causes include dam exhaustion, stretching of the uterus from large or prior litters, calcium or glucose deficiencies, or other systemic disease.
When can you give oxytocin?
– once hydration status/electrolyte abnormalities have been addressed
– obstruction of the birth canal has been ruled out
Uterine torsion
defined as rotation of the uterus by more than 45° around the long axis.
– most commonly occurs with pregnancy but can occur without it as well
– reported to occur with pyometra, polyps, and trauma in small animals
Uterine torsion treatment
– Intravenous fluid therapy and analgesia are the first step in treatment for uterine torsion
– eral anesthesia and ovariohysterectomy is the treatment of choice for uterine torsion.
Uterine Prolapse
– protrusion of the uterus, through the cervix, to the outside of the body
– One or both uterine horns can prolapse
– rare condition but appears more commonly in the cat than the dog
– most often during parturition or shortly after, as the cervix is open.
– or with dystocia, metritis, or with retained placenta
